US4054479A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Additive process for producing printed circuit elements using a self-supported photosensitive sheet
Assignee: EIDP Inc
•
Filing: 1976-12-22
•
Granted: 1977-10-18
•
Expires: 1996-12-22
Abstract
Abstract Printed circuit boards with plated through-holes are prepared by an electroless plating process using a self-supported, adherent, photohardenable sheet. The self-supported photohardenable sheet preferably is composed of a photopolymerizable material and may be a thick, homogeneous sheet or it may be a sheet reinforced with a foraminous material therein. The self-supported sheet is imagewise exposed to actinic radiation to form an adherent circuit pattern thereon comprising the unexposed areas. Through-holes are introduced into the pad areas of the circuit pattern, powdered catalyst is applied to the adherent pattern and through-holes and the catalytic image is plated in an electroless plating bath. The self-supported sheet may be used without additional catalyzing steps to make single sided, two-sided or multilayered printed circuit boards with plated throughholes and interconnections.
Inventors
- 👤 Robert William Peiffer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:11
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/10; H05K3/18; H05K3/181; H05K3/182; H05K3/185
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
96 words
A process for preparing printed circuit boards having plated through-holes from a self-supported, adherent, photohardenable sheet which comprises, in either order, 1. exposing a surface of the self-supported sheet imagewise to actinic radiation to reduce adherence of the areas receiving radiation; and 2. introducing through-holes into the sheet; then 3. applying to the surface of the sheet and the through-holes therein a material catalytic to electroless plating which adheres to the underexposed surface and the hole areas; and 4. applying electroless plating solution to the catalytic image and through-hole surfaces to produce an electrically conductive circuit.
Claim 2
Dependent Claim
96 words
A process for preparing printed circuit boards having plated through-holes from a self-supported, adherent, photohardenable sheet which comprises, in either order, 1. exposing a surface of the self-supported sheet imagewise to actinic radiation to reduce adherence of the areas receiving radiation; and 2. introducing through-holes into the sheet; then 3. applying to the surface of the sheet and the through-holes therein a material catalytic to electroless plating which adheres to the underexposed surface and the hole areas; and 4. applying electroless plating solution to the catalytic image and through-hole surfaces to produce an electrically conductive circuit.
Claim 3
Dependent Claim
19 words
A process according to claim 1 wherein the self-supported adherent, photohardenable sheet is a substantially homogeneous, solid, photohardenable sheet.
Claim 4
Dependent Claim
19 words
A process according to claim 1 wherein the self-supported adherent, photohardenable sheet is reinforced with a a foraminous material.
Claim 5
Dependent Claim
14 words
A process according to claim 3 wherein the foraminous material is a nonwoven fabric.
Claim 6
Dependent Claim
14 words
A process according to claim 3 wherein the foraminous material is a woven cloth.
Claim 7
Dependent Claim
12 words
A process according to claim 3 wherein the foraminous material is paper.
Claim 8
Dependent Claim
34 words
A process according to claim 1 wherein the photohardenable sheet is a photopolymerizable sheet comprised of an addition-polymerizable, ethylenically unsaturated compound, a macromolecular orgnanic polymer binder, and a polymerization initiator activatable by actinic radiation.
Claim 9
Dependent Claim
22 words
A process according to claim 1 wherein after step (3) the sheet is baked to harden the underexposed areas of the sheet.
Claim 10
Dependent Claim
126 words
A process for preparing printed circuit boards having plated through-holes from a self-supported photopolymerizable sheet having on each surface a removable cover film which comprises, in either order, 1. exposing a surface of the reinforced sheet imagewise to actinic radiation; and 2. introducing through-holes into the sheet; then 3. removing the removable cover film from the exposed side of the sheet without transfer thereto of exposed or underexposed areas of the photopolymerizable material; 4. applying to the surface of the sheet and the through-holes therein a material catalytic to electroless plating which adheres to the underexposed surface and the hole areas; 5. removing the second removable cover film; and 6. applying electroless plating solution to the catalyzed areas and through-holes to produce an electrically conductive circuit.
Claim 11
Dependent Claim
126 words
A process for preparing printed circuit boards having plated through-holes from a self-supported photopolymerizable sheet having on each surface a removable cover film which comprises, in either order, 1. exposing a surface of the reinforced sheet imagewise to actinic radiation; and 2. introducing through-holes into the sheet; then 3. removing the removable cover film from the exposed side of the sheet without transfer thereto of exposed or underexposed areas of the photopolymerizable material; 4. applying to the surface of the sheet and the through-holes therein a material catalytic to electroless plating which adheres to the underexposed surface and the hole areas; 5. removing the second removable cover film; and 6. applying electroless plating solution to the catalyzed areas and through-holes to produce an electrically conductive circuit.
Claim 12
Dependent Claim
120 words
A process for the preparation of complementary printed circuits on each side of a self-supported photopolymerizable shet having on each surface a removable cover film, which comprises, in either order, 1. exposing both surfaces of the self-supporting sheet imagewise to actinic radiation to reduce adherence of the areas receiving radiation; and 2. introducing through-holes into the sheet; then 3. removing the removable cover films without transfer of exposed or underexposed areas of the photopolymerizable material; 4. applying to both surfaces of the sheet and the through-holes therein a material catalytic to electroless plating which adheres to the underexposed surfaces and the hole areas; 5. applying electroless plating solution to the catalyzed areas and through-holes to produce an electrically conductive circuit.
Claim 13
Dependent Claim
120 words
A process for the preparation of complementary printed circuits on each side of a self-supported photopolymerizable shet having on each surface a removable cover film, which comprises, in either order, 1. exposing both surfaces of the self-supporting sheet imagewise to actinic radiation to reduce adherence of the areas receiving radiation; and 2. introducing through-holes into the sheet; then 3. removing the removable cover films without transfer of exposed or underexposed areas of the photopolymerizable material; 4. applying to both surfaces of the sheet and the through-holes therein a material catalytic to electroless plating which adheres to the underexposed surfaces and the hole areas; 5. applying electroless plating solution to the catalyzed areas and through-holes to produce an electrically conductive circuit.
Claim 14
Dependent Claim
85 words
A process for the preparation of multilayered printed circuit boards with plated through-holes from a self-supported, adherent, photopolymerizable sheet having on each surface a removable cover film which comprises, 1. exposing the self-supported, adherent, photopolymerizable sheet through the cover film imagewise to actinic radiation; 2. removing the cover film; 3. applying finely divided catalyst material to the surface to form a catalytic image; 4. treating the catalytic image with an electroless plating solution to form a printed circuit substrate; then, using the printed circuit substrate,
Claim 15
Dependent Claim
85 words
A process for the preparation of multilayered printed circuit boards with plated through-holes from a self-supported, adherent, photopolymerizable sheet having on each surface a removable cover film which comprises, 1. exposing the self-supported, adherent, photopolymerizable sheet through the cover film imagewise to actinic radiation; 2. removing the cover film; 3. applying finely divided catalyst material to the surface to form a catalytic image; 4. treating the catalytic image with an electroless plating solution to form a printed circuit substrate; then, using the printed circuit substrate,
Claim 16
Dependent Claim
104 words
laminating the surface of an adherent, photohardenable layer of a photohardenable element comprising an adherent photohardenable layer and a strippable cover film thereon, to the printed circuit substrate; then, in either order, 6. imagewise exposing the laminated element through the cover film to actinic radiation; and 7. introducing through-holes into the laminated element; then 8. removing the strippable cover film; 9. applying divided catalyst material to the surface and the through-holes to form a catalytic image; 10. treating the catalytic image and holes with an electroless plating solution to form a conductive printed circuit and holes; and 11. curing the laminated element by baking.
Claim 17
Dependent Claim
104 words
laminating the surface of an adherent, photohardenable layer of a photohardenable element comprising an adherent photohardenable layer and a strippable cover film thereon, to the printed circuit substrate; then, in either order, 6. imagewise exposing the laminated element through the cover film to actinic radiation; and 7. introducing through-holes into the laminated element; then 8. removing the strippable cover film; 9. applying divided catalyst material to the surface and the through-holes to form a catalytic image; 10. treating the catalytic image and holes with an electroless plating solution to form a conductive printed circuit and holes; and 11. curing the laminated element by baking.
Claim 18
Dependent Claim
31 words
A process according to claim 11 wherein steps 5, 6, 8, 9 and 10 are carried out at least once before the complete sequence of steps 5 through 10 are completed.
References Cited (Backward Citations)
US3436468A
Cited
US3615471A
Cited
US3646572A
Cited
US3778900A
Cited
US3956041A
Cited
US3934335A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-17 | 1981-04-18 | 1981-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-17 | 1985-04-18 | 1985-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-17 | 1989-04-18 | 1989-10-18 | $7700.00 | Window Closed / Lapsed |